Electronic Telegram No. 3109
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2011 KP_36 (SPACEWATCH)
     An apparently asteroidal object discovered by T. H. Bressi on Spacewatch
telescope images obtained a year ago at Kitt Peak (discovery observations
tabulated below), and designated 2011 KP36 when announced on MPS 385381, has
been found to show cometary appearance in recent images obtained by CCD
astrometrists elsewhere.  Sixty stacked 30-s images taken by R. Holmes
(Ashmore, IL, USA, 0.81-m f/4 astrograph) on Apr. 19.4 UT (and measured by T.
Vorobjov, L. Buzzi, and S. Foglia) show that the object appears to be diffuse
with a coma of diameter 6" with a faint tail 9" in p.a. 10 degrees.  Luca
Buzzi (Varese, Italy, 0.38-m f/6.8 reflector) writes that stacked images taken
on Apr. 21.1 show that the object appears visually softer than images of
nearby stars; it has a very condensed coma with a faint coma 13" wide.  Buzzi
adds that four stacked 180-s exposures taken in very good conditions by P.
Miller, P. Roche, A. Tripp, R. Miles, R. Holmes, S. Foglia, and himself with
the 2.0-m f/10 "Faulkes Telescope North" at Haleakala on Apr. 20.61 shows
again the soft aspect of the comet, with a faint coma 7" wide.  Vorobjov also
stacked six 120-s exposures that he obtained on May 17.3 with a 1.3-m f/13
Cassegrain reflector at Kitt Peak, showing the object to be diffuse with a 8"
coma of red mag 19.1-19.5 and a hint of tail in p.a. 80 deg.

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     May  21.32534   16 30 05.91   - 1 54 40.9   20.4   Bressi
          21.34309   16 30 05.63   - 1 54 39.9   20.4     "
          21.36085   16 30 05.36   - 1 54 39.0   20.2     "
          25.27352   16 29 07.25   - 1 51 01.6   21.2     "
          25.29121   16 29 06.97   - 1 51 01.1   20.5     "
          25.30892   16 29 06.72   - 1 51 00.4   20.8     "

Additional astrometry, the following orbital elements by G. V. Williams, and
an ephemeris appear on MPEC 2012-K12.

                    Epoch = 2016 May  12.0 TT
     T = 2016 May  27.90578 TT        Peri. = 180.60076
     e = 0.8721094                    Node  = 173.40584 2000.0
     q = 4.8856950 AU                 Incl. =  18.98722


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 May 17                      (CBET 3109)              Daniel W. E. Green